2023 TOYOTA SIENNA HYBRID overheating

992-1. Instrument cluster
2
Vehicle status information and indicators
eration” refers to the conversion of
energy created by the movement
of the vehicle into electrical
energy.
In the following situ ation, the Hybrid
System Indicator does not operate.
●“READY” indicator is not illumi-
nated.
●The shift lever is in a range other
than D or S.
■Outside temperature display
●In the following si tuations, the cor-
rect outside tempe rature may not
be displayed, or the display may
take longer than normal to
change.
• When stopped, or driving at low speeds (less than 12 mph [20
km/h])
• When the outside temperature has changed suddenly (at the
entrance/exit of a garage, tunnel,
etc.)
●When “--” or “E” is displayed, the
system may be malfunctioning.
Take your vehicle to your Toyota
dealer.
●Displays the outside temperature
within the range of -40°F (-40°C)
to 122°F (50°C).
●When the outside temperature is
approximately 37°F (3°C) or
lower, the low outside temperature
indicator will flash for approxi-
mately 10 seconds , then stay on.
■Liquid crystal display
 P.105Switches the items of the odom-
eter, trip meter A, trip meter B
and oil maintenance by pressing
the “ODO TRIP” switch.
When the trip meter is dis-
played, pressing and holding the
switch will reset the trip meter.
WARNING
■The information display at
low temperatures
Allow the interior of the vehicle to
warm up before using the liquid
crystal information display. At
extremely low temperatures, the
display monitor may respond
slowly, and display changes may
be delayed.
For example, there is a lag
between the driver’s shifting and
the new shift range appearing on
the display. This lag could cause
the driver to downshift again,
causing rapid and excessive
engine braking and possibly an
accident resulting in death or
injury.
NOTICE
■To prevent damage to the
engine and its components
The engine may be overheating if
the engine coolant temperature
gauge is in the red zone (“H”). In
this case, immediately stop the
vehicle in a safe place, and check
the engine after it has cooled
completely. ( P.509)
Changing the trip meter
display

1032-1. Instrument cluster
2
Vehicle status information and indicators
energy.
In the following situ ation, the Hybrid
System Indicator does not operate.
●“READY” indicator is not illumi-
nated.
●The shift lever is in a range other
than D or S.
■Outside temperature display
●In the following si tuations, the cor-
rect outside tempe rature may not
be displayed, or the display may
take longer than normal to
change.
• When stopped, or driving at low speeds (less than 12 mph [20
km/h])
• When the outside temperature has changed suddenly (at the
entrance/exit of a garage, tunnel,
etc.)
●When “--” or “E” is displayed, the
system may be malfunctioning.
Take your vehicle to your Toyota
dealer.
●Displays the outside temperature
within the range of -40°F (-40°C)
to 122°F (50°C).
●When the outside temperature is
approximately 37°F (3°C) or
lower, the low outside temperature
indicator will flash for approxi-
mately 10 seconds , then stay on.
■Liquid crystal display
 P.105
■Customization
Settings (e. g. meter display) can be
changed on the screen of the
multi-informat ion display. (P.539)Switches the items of the odom-
eter, trip meter A, trip meter B
and oil maintenance by pressing
the “ODO TRIP” switch.
When the trip meter is dis-
played, pressing and holding the
switch will reset the trip meter.
WARNING
■The information display at
low temperatures
Allow the interior of the vehicle to
warm up before using the liquid
crystal information display. At
extremely low temperatures, the
display monitor may respond
slowly, and display changes may
be delayed.
For example, there is a lag
between the driver’s shifting and
the new shift range appearing on
the display. This lag could cause
the driver to downshift again,
causing rapid and excessive
engine braking and possibly an
accident resulting in death or
injury.
NOTICE
■To prevent damage to the
engine and its components
The engine may be overheating if
the engine coolant temperature
gauge is in the red zone (“H”). In
this case, immediately stop the
vehicle in a safe place, and check
the engine after it has cooled
completely. ( P.509)
Changing the trip meter
display

2154-1. Before driving
4
Driving
WARNING
●Do not leave a door or window
open if the curved glass is
coated with a metallized film
such as a silver-colored one.
Reflected sunlight may cause
the glass to act as a lens, caus-
ing a fire.
●Always apply the parking brake,
shift the shift lever to P, stop the
hybrid system and lock the vehi-
cle.
Do not leave the vehicle unat-
tended while the “READY” indi-
cator is illuminated.
If the vehicle is parked with the
shift lever in P but the parking
brake is not set, the vehicle may
start to move, possibly leading
to an accident.
●Do not touch the exhaust pipes
while the “READY” indicator is
illuminated or immediately after
turning the hybrid system off.
Doing so may cause burns.
■When taking a nap in the
vehicle
Always turn the hybrid system off.
Otherwise, if you accidentally
move the shift lever or depress
the accelerator pedal, this could
cause an accident or fire due to
hybrid system overheating. Addi-
tionally, if the vehicle is parked in
a poorly ventilated area, exhaust
gases may collect and enter the
vehicle, leading to death or a seri-
ous health hazard.
■When braking
●When the brakes a re wet, drive
more cautiously.
Braking distance increases
when the brakes are wet, and
this may cause one side of the
vehicle to brake differently than
the other side. Also, the parking
brake may not securely hold the
vehicle.
●If the electronically controlled
brake system does not operate,
do not follow other vehicles
closely and avoid hills or sharp
turns that require braking.
In this case, braking is still pos-
sible, but the brake pedal
should be depressed more
firmly than usual. Also, the brak-
ing distance will increase. Have
your brakes fixed immediately.
●The brake system consists of 2
or more individual hydraulic sys-
tems; if one of the systems fails,
the other will still operate. In this
case, the brake pedal should be
depressed more firmly than
usual and the braking distance
will increase. Have your brakes
fixed immediately.
■If the vehicle becomes stuck
(AWD models)
Do not spin the wheels exces-
sively when any of the tires is up
in the air, or the vehicle is stuck in
sand, mud, etc. This may damage
the driveline components or pro-
pel the vehicle forward or back-
ward, causing an accident.
NOTICE
■When driving the vehicle
●Do not depress the accelerator
and brake pedals at the same
time during driving, as this may
restrain the hybrid system out-
put.
●Do not use the accelerator
pedal or depress the accelera-
tor and brake pedals at the
same time to hold the vehicle on
a hill.

2314-1. Before driving
4
Driving
down too long or applying the
brakes too frequently. This
could cause the brakes to
overheat and result in
reduced braking efficiency.
 Due to the added load of the
trailer, your vehicle’s hybrid
system may overheat on hot
days (at temperatures over
85°F [30°C]) when driving up
a long or steep grade. If the
engine coolant temperature
gauge indicates overheating,
immediately turn off the air
conditioning (if in use), pull
your vehicle off the road and
stop in a safe spot. ( P.509)
 Always place wheel blocks
under both the vehicle’s and
the trailer’s wheels when
parking. Apply the parking
brake firmly, and put the
transmission in P. Avoid park-
ing on a slope, but if unavoid-
able, do so only after
performing the following:
1 Apply the brakes and keep
them applied.
2 Have someone place wheel
blocks under both the vehi-
cle’s and trailer’s wheels.
3 When the wheel blocks are in
place, release the brakes
slowly until the blocks absorb
the load.
4 Apply the parking brake
firmly. 5
Shift into P and turn off the
hybrid system.
 When restarting after parking
on a slope:
1 With the transmission in P,
start the hybrid system. Be
sure to keep the brake pedal
depressed.
2 Shift into a forward gear. If
reversing, shift into R.
3 If the parking brake is in man-
ual mode, release the park-
ing brake. ( P.246)
4 Release the brake pedal, and
slowly pull or back away from
the wheel blocks. Stop and
apply the brakes.
5 Have someone retrieve the
blocks.
■Break-in schedule
If your vehicle is new or equipped
with any new power train compo-
nents (such as an engine, transmis-
sion, differential or wheel bearing),
Toyota recommends that you do not
tow a trailer until the vehicle has
been driven for over 500 miles (800
km).
After the vehicle has been driven for
over 500 miles (800 km), you can
start towing. However, for the next
500 miles (800 km), drive the vehi-
cle at a speed of less than 45 mph
(72 km/h) when towing a trailer, and
avoid full throttle acceleration.
■Maintenance
●If you tow a traile r, your vehicle
will require more fr equent mainte-
nance due to the additional load.
(See “Scheduled Maintenance
Guide” or “Owner ’s Manual Sup-
plement”.)

2484-2. Driving procedures
■If “Parking Brake Unavailable”
is displayed on the multi-infor-
mation display
Operate the parking brake switch. If
the message does not disappear
after operating the switch several
times, the system may be malfunc-
tioning. Have the vehicle inspected
by your Toyota dealer.
■Parking brake operation sound
When the parking brake operates, a
motor sound (whirring sound) may
be heard. This does not indicate a
malfunction.
■Parking brake indicator light
●Depending on the power switch
mode, the parking brake indicator
light will turn on and stay on as
described below:
ON: Comes on until the parking
brake is released.
Not in ON: Stays on for approxi-
mately 15 seconds.
●When the power switch is turned
off with the parking brake set, the
parking brake indicator light will
stay on for about 15 seconds. This
does not indicate a malfunction.
■When the parking brake switch
malfunctions
Automatic mode (automatic brake
setting and releas ing) will be turned
on automatically.
■Parking the vehicle
 P.210
■Parking brake engaged warning
buzzer
A buzzer will sound if the vehicle is
driven with the parking brake
engaged. “Parking Brake ON” is dis-
played on the multi-information dis-
play (with the vehicle reaching a
speed of 3 mph [5 km/h]).
■If the brake system warning
light comes on
 P.464
■Usage in winter time
 P.345
WARNING
■When parking the vehicle
Do not leave a child in the vehicle
alone. The parking brake may be
released unintentionally by a child
and there is the danger of the
vehicle moving that may lead to
an accident resulting in death or
serious injury.
■Parking brake switch
Do not set any objects near the
parking brake switch. Objects
may interfere with the switch and
may lead the parking brake to
unexpectedly operate.
NOTICE
■When parking the vehicle
Before you leave the vehicle, shift
the shift lever to P, set the parking
brake and make s ure that the
vehicle does not move.
■When the system malfunc-
tions
Stop the vehicle in a safe place
and check the warning messages.
■When the parking brake can-
not be released due to a mal-
function
Driving the vehicle with the park-
ing brake set will lead to brake
components overheating, which
may affect braking performance
and increase brake wear. Have
the vehicle inspected by your
Toyota dealer immediately if this
occurs.

3384-5. Using the driving support systems
■Sounds and vibrations caused
by the ABS, brake assist, VSC,
TRAC, Trailer Sway Control and
hill-start assist control systems
●A sound may be heard from the
engine compartment when the
brake pedal is dep ressed repeat-
edly, when the hybrid system is
started or just after the vehicle
begins to move. This sound does
not indicate that a malfunction has
occurred in any of these systems.
●Any of the following conditions
may occur when t he above sys-
tems are operating. None of these
indicates that a malfunction has
occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard also after the vehicle comes to a stop.
■ECB operating sound
ECB operating sound may be heard
in the following cases, but it does
not indicate that a malfunction has
occurred.
●Operating sound heard from the
engine compartment when the
brake pedal is operated.
●Motor sound of the brake system
heard from the front part of the
vehicle when the driver’s door is
opened.
●Operating sound heard from the
engine compartment when one or
two minutes passed after the stop
of the hybrid system.
■Active Cornering Assist opera-
tion sounds and vibrations
When the Active Cornering Assist is
operated, operation sounds and
vibrations may b e generated from
the brake system, but this is not a
malfunction.
■EPS operation sound
When the steering wheel is oper-
ated, a motor sou nd (whirring
sound) may be heard. This does not
indicate a malfunction.
■Automatic reactivation of
TRAC, Trailer Sway Control and
VSC systems
After turning the TRAC, Trailer
Sway Control and VSC systems off,
the systems will be a utomatically re-
enabled in the following situations:
●When the power switch is turned
off
●If only the TRAC sy stem is turned
off, the TRAC will turn on when
vehicle speed increases
If both the TRAC and VSC sys-
tems are turned of f, automatic re-
enabling will not occur when vehi-
cle speed increases.
■Operating conditions of Active
Cornering Assist
The system operates when the fol-
lowing occurs.
●TRAC/VSC can operate
●The driver is attempting to accel-
erate while turning
●The system detects that the vehi-
cle is drifting to the outer side
●The brake pedal is released
■Reduced effectiveness of the
EPS system
The effect iveness of the EPS sys-
tem is reduced to prevent the sys-
tem from overheating when there is
frequent steering input over an
extended period of time. The steer-
ing wheel may feel heavy as a
result. Should this occur, refrain
from excessive steering input or
stop the vehicle a nd turn the hybrid
system off. The EPS system should
return to normal within 10 minutes.
■Secondary Collision Brake
operating conditions
The system operates when the SRS
airbag sensor de tects a collision
while the vehicle is in motion. How-
ever, the system does not operate
when the components are dam-
aged.

3394-5. Using the driving support systems
4
Driving
■Secondary Collision Brake
automatic cancellation
The system is automatically can-
celed in any of th e following situa-
tions.
●The vehicle speed drops to
approximately 6 mph (10 km/h).
●A certain amount of time elapses
during operation
●The accelerator pedal is
depressed a large amount
■If a message about AWD is
shown on the multi-information
display (AWD models)
Perform the following actions.
●“AWD System Overheated
Switching to 2WD Mode”
AWD system is overheated. Stop
the vehicle in a safe place with the
hybrid system operating.
*
If the message disappears after a
while, there is n o problem. If the
message remains, have the vehicle
inspected by your Toyota dealer
immediately.
●“AWD System Overheated 2WD
Mode Engaged”
AWD system has been temporarily
released and switched to front-
wheel drive due to overheating.
Stop the vehicle in a safe place with
the hybrid system operating.
*
If the message disappears after a
while, AWD system will automati-
cally recover. If the message
remains, have the vehicle inspected
by your Toyota dealer immediately.
●“AWD system Malfunction 2WD
Mode Engaged Visit Your Dealer”
A malfunction occurs in the AWD
system. Have the vehicle inspected
by your Toyota dealer immediately.
*: When stopping the vehicle, do not stop the hybrid system until the
display message has turned off.
WARNING
■The ABS does not operate
effectively when
●The limits of tire gripping perfor-
mance have been exceeded
(such as excessively worn tires
on a snow covered road).
●The vehicle hydroplanes while
driving at high speed on wet or
slick roads.
■Stopping distance when the
ABS is operating may exceed
that of normal conditions
The ABS is not designed to
shorten the vehicle’s stopping dis-
tance. Always maintain a safe dis-
tance from the veh icle in front of
you, especially in the following sit-
uations:
●When driving on dirt, gravel or
snow-covered roads
●When driving with tire chains
●When driving over bumps in the
road
●When driving over roads with
potholes or uneven surfaces
■TRAC/VSC may not operate
effectively when
Directional control and power may
not be achievable while driving on
slippery road surfaces, even if the
TRAC/VSC system is operating.
Drive the vehicle carefully in con-
ditions where stability and power
may be lost.

Alphabetical Index571
Seat belts ............................. 399
Clock ............................... 100, 104
Coat hooks .............................. 388
Condenser .............................. 417
Console box ............................ 367
Consumption screen.............. 122
Conversation mirror ............... 370
Coolant Checking .............................. 416
Preparing and c hecking before
winter.................................. 344
Warning light ........................ 465
Cooling system ...................... 416 Hybrid system overheating... 509
Cruise control Dynamic radar cruise control with full-speed range .......... 291
Cup holders ............................ 368
Current fuel consumption ..... 125
Current fuel economy ............ 106
Curtain shield airbags ............. 41
Customizable features ........... 538
D
Daytime running light system251 Replacing light bulbs ............ 448
Defogger Outside rear view mirrors ..... 350
Rear window ........................ 350
Windshield............................ 349
Digital Rear-view Mirror ......... 189 Adjustment ........................... 191
Cleaning ............................... 194
Dinghy towing ........................ 232
Display BSM (Blind Spot Monitor)..... 303
Consumption screen ............ 122
Driving information ............... 106
Dynamic radar cruise control with full-speed range .......... 291
Energy monitor ..................... 122
Head-up display ................... 118 Intuitive parking assist ..........312
LTA (Lane Traci
ng Assist) ....284
Multi-information display.......104
RCD (Rear Camera Detection) ...........................................320
RCTA (Rear Cross Traffic Alert) ...........................................303
Warning messages ...............475
Do-it-yourself maintenance .403, 408
Door lock Back door .............................150
Front doors ...........................132
Sliding doors.........................137
Smart key system .................165
Wireless remote control........130
Door pockets...........................370
Doors Automatic door locking and unlocking system ................136
Back door .............................150
Door glasses ........................202
Door lock ..............................132
Front doors ...........................132
Open door warning buzzer ...136
Outside rear view mirrors .....199
Sliding door child-protectors .142
Sliding doors.........................137
Driver’s seat belt reminder light ...............................................471
Drive-start control ..................211
Driving Break-in tips .........................211
Correct posture .......................33
Driving mode select switch ...334
Hybrid Electric Vehicle driving tips ......................................342
Procedures ...........................210
Winter drive tips....................344
Driving informatio n display ...106
Driving mode select switch ...334
Driving position memory .......179